1. Field of Disclosure
This disclosure is directed to busways used in data centers, and more particularly to a busway plug-in unit having recessed movable jaws for connecting the plug-in unit to a busway without having to power down (“off”) the busway, and to a method of installing, removing and replacing the plug-in unit on the busway.
2. Discussion of Related Art
Busway electrical distribution systems are well known in the art of electrical distribution. Busway systems are comprised of a number of factory assembled sections, each including a number of individually insulated generally flat electrical conductors or busbars stacked one upon another and enclosed within a housing which provides protection and support for the busbars. For example, typical powerbus busway systems have ten-foot (or four-foot) sections of flat, stacked, electrical conductors for transporting electrical energy from a point A to a point B, while distributing the electrical energy to various electrical loads. Busway construction is modular, and, in many ways, is superior to cable and conduit systems from an installation standpoint.
For distribution of the electrical energy, the busway sections include one or more plug-in outlets having a plurality of conductive contact points on the internal busbars. In general, the plug-in outlets include openings that are provided through the housing of the busway system at each of a plurality of power tap-off sections to expose conductive material of the busbars for connection with an appropriate connecting jaw. A plug-in unit, which is used to tap off power from the busway, is attached to the plug-in opening by mounting a plurality of jaws to the respective busbars.
When adding, removing or replacing the plug-in unit to and from the busway, it is advised or sometimes required to power down the busway prior to performing one of these functions. As busways are used increasingly within data centers, the requirement to have to first power down the powerbus busway before making any changes to the plug-in unit population is somewhat onerous, since powering down the powerbus busway means a portion of the data center is down for operation. The temptation may exist to ignore this requirement and perform “live work” by “hot swapping” the plug-in unit.
One approach used to prevent the temptation of not powering down the busway is to place numerous warning labels on the equipment and within the installation manual associated with the plug-in unit. Such warnings encourage the person installing the plug-in unit to first power down the powerbus busway before making any changes. A disadvantage associated with this approach is that “hot swapping” still occurs despite the warnings due to the installer's desire to maintain a high level of uptime in the data center.
Another approach is for the installer or operator to have two separate feeds, and to employ one feed when powering down the other feed. A disadvantage associated with this approach is that there is no redundancy when one feed is powered down.